This NSA classification guide, dated 21 November 2011, covers signals intelligence material that as to be kept secret for more than the standard 60 years: see the Der Spiegel article The NSA in Germany: Snowden’s Documents Available for Download, 18 June 2014.

This document lists the 193 governments, intragovernmental organisations and other entities which the NSA was granted the legal authority to intercept communications “about” for foreign intelligence purposes in August 2010: see the Washington Post article Court gave NSA broad leeway in surveillance, 30 June 2014.